Convoy Accessories Review - IMHO YMMV
Clip-on Clip https://www.aliexpress.com/item/1005002413109298.html?spm=a2g0o.order_list.0.0.21ef1802cowKTq A little too small at 22 mm diameter so I could see a little air gap between clip and light. I would have preferred probably 25 mm. Fits S21D, M21E (after bending clipping arms outward a little). Might fit M21B and M21F but I didn’t try because it’s tight and I didn’t want to scratch the finish. I much prefer the screw on clip (better in every way IMHO), but if this is what you like, I would bend the arms outward a little so that it doesn’t scratch the light’s finish.
Screw-on Clip https://www.aliexpress.com/item/1005002434411703.html?spm=a2g0o.order_list.0.0.21ef1802dSS6ZX Perfect for my need. Fits S21D, M21B perfectly, does fit M21F and likely E, but would help if the screws are a little longer for absolute secure attachment. Ok I hope what follows makes sense: For the Convoys with the side switch, M21E and M21F, I prefer to keep the clip at 9 o’clock position (90 degrees to the left of the switch) so that it doesn’t go under my right hand grip. For the M21E the holes are perfectly placed so I use screw-on. For the M21F the holes are not, so I use the clip-on, after I’ve bent the clipping arms outward.
Metal lighted switch https://www.aliexpress.com/item/1005002389032527.html?spm=a2g0o.order_list.0.0.21ef1802dSS6ZX IMHO mandatory for S21D and M21B. For switch color I chose blue because of less current drain vs orange (9.4 mA vs 14 mA). The metal switch has a wonderful nicely tactile click, more defined in its action and night and day better than the rubber version. For me, it is especially critical for the 12-GROUPS UI used in these lights because in this UI both click (full click) and tap (half press) are important, and the tap is so much easier with it. The metal switch has a built in half-way stop for the tap’s half press and it makes all the difference IMHO. Install takes 5 minutes, completely plug and play. The most challenging step is to remove the retaining ring which is very tight and would likely be difficult if you don’t have something similar to this needle point pliers https://www.amazon.com/gp/product/B000JNRR0Y/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1 .