For every product preserving bundle functor $T^{\mu }$ on fibered manifolds, we describe the underlying functor of any order $(r,s,q),s\ge r\le q$. We define the bundle $K_{k,l}^{r,s,q}Y$ of $(k,l)$-dimensional contact elements of the order $(r,s,q)$ on a fibered manifold $Y$ and we characterize its elements geometrically. Then we study the bundle of general contact elements of type $\mu$. We also determine all natural transformations of $K_{k,l}^{r,s,q}Y$ into itself and of $T\left(K_{k,l}^{r,s,q}Y\right)$ into itself and we find all natural operators lifting projectable vector fields and horizontal...

A natural $T$-function on a natural bundle $F$ is a natural operator transforming vector fields on a manifold $M$ into functions on $FM$. For any Weil algebra $A$ satisfying $dimM\ge \mathrm{w}idth\left(A\right)+1$ we determine all natural $T$-functions on $T^{*}{T}^{A}M$, the cotangent bundle to a Weil bundle $T^{A}M$.