local alpha = 255 

bindKey ( "aim_weapon", "both", 
function ( _, state ) 
if getPedWeaponSlot ( localPlayer ) == 6 then 
if ( state == "down" ) then 
alpha = 0 
elseif ( state == "up" ) then 
alpha = 255 
end 
for _, v in ipairs ( getElementsByType ( "object", root, true ) ) do 
if isElementAttachedToBone ( v ) then 
local id = getElementModel ( v ) 
if ( id == 2708 ) then 
setElementAlpha ( v, alpha ) 
end 
end 
end 
end 
end )