AS01 arm strap is suitable for OrcaTorch D510, D800 and D810. It is also suitable for flashlight diameter 30-40mm. Friendly Tips: If you are going to use the dive light with this arm strap, we suggest you make sure attach the light securely to the arm strap with a landyard. The wrist strap is to free your hand, while the landyard can prevent the light from falling off the arm strap. Featuring One size suitable for most of flashlights which diameter bettween30-40mm For use with or without gloves, can be used on left or right hand freely The thickened but soft durable canvas can fix the flashlight with your hand tightly, free your hand in the water, really comfortable Fast dry after use, magic tape design,very easy to operate