Rheostat light screws into Hogg Wrap directly. Three_settings provide optimum brightness for a multiple_of situations. Rheostat Sight Light - SL The perfect fix for poor lighting. The 3 things you need for ultimate accuracy are what the Spot-Hogg Sight illuminates. Your pins, alignment ring and level will always be visible with the aid of a variable brightness rheostat system. Compatible with all Spot-Hogg models.